BEIJING, Aug. 10 -- There might have been a more spectacular and thoroughly dominant manner in which Michael Phelps could have begun his Olympics on Sunday morning, but that seems unlikely. In an event in which he was supposed to be pushed, he had no peers. In a race in which there was to be stress, he became the picture of relaxation, so at odds with the feat he accomplished.

With President Bush, the first lady and former president George H.W. Bush in the stands waving American flags, Phelps won the 400-meter individual medley at the National Aquatics Center in a world record time of 4 minutes 3.84 seconds -- crushing his old world mark, winning an Olympic gold medal and likely sending chills through the rest of the competitors on hand, many of whom could succumb to Phelps in similar fashion later in the meet.

The victory over Hungary's Laszlo Cseh and fellow American Ryan Lochte gave Phelps the first gold in his first event here, and served as a no-doubt example of how prepared he is. Three other finals were scheduled for later in Sunday's session, and Australia's Stephanie Rice set her own world record in winning the women's 400 IM, taking gold to the bronze of Towson, Md., product Katie Hoff. And the American 4x100-meter freestyle relay team -- anchored by 41-year-old Dara Torres -- took silver behind the Netherlands, ahead of the favored Australians. Still, the focus of the swimming events -- and, in some ways, the entire Olympic competition here -- is on Phelps, the 23-year-old from Baltimore County who seeks a record eight golds.

"To be honest, I didn't really feel that great," Phelps said immediately afterward. That alone is intimidating. Though Phelps trailed at various points during the first half of the medley -- which combines all four of swimming's disciplines: butterfly, backstroke, breaststroke and freestyle -- he faced no threat over the final 100 meters. Cseh, the bronze medalist in 2004 in Athens, and Lochte, who pushed Phelps to a world record during U.S. trials in Omaha earlier in the summer, were both expected to provide stout competition. Yet as Phelps hit his freestyle leg, he grew more distant.

That was not entirely expected. Of Phelps's eight events here, the 400 IM shaped up to be perhaps the most challenging of his five individual races. (He will also swim three relays.) Yes, he won gold in Athens in 2004 in the event, the first of his six gold medals there. Sure, he first snatched the world record in 2002 as a 17-year-old, and he hasn't given it up since, lowering it himself seven times now. And indeed, he now owns seven of the nine fastest times in the race.

Yet over the last 50 meters, not only did the world record feel inevitable -- Phelps beat his old mark by a remarkable 1.41 seconds -- but the opposition appeared almost feeble. By the time Cseh took silver, Phelps -- who arrived 2.32 seconds earlier -- had already looked at the clock and digested his accomplishment. On his face came a smile. The meet, and his quest, had begun perfectly.

"Going into the ready room, I started getting these kind of like chills up my body," Phelps said. "Right then and there, I knew I was starting to get more and more excited. I was pretty emotional after that race."

That in itself is a rare occurrence. All week -- in fact, all summer and even earlier -- Phelps has played down his task, which is merely to make history. In 1972 in Munich, Californian Mark Spitz swam in seven events and won seven gold medals. No Olympian, in any sport, has ever won that many in a single Games. Not before or since. Not in winter or summer.